An Ethiopian Airlines Boeing 737-800 crashed shortly after taking off from Beirut's Rafik Hariri International Airport. The plane took off during a severe thunderstorm and crashed into the Mediterranean Sea in the early hours of Monday morning, January 25. It has been suggested that the plane was struck by lightning.
The exact cause of the crash remains unknown, however, pending further investigations.
The Ethiopian Airlines Boeing 737-800 is a modern jet aircraft. The plane, built in 2002, had completed more than 25,000 flight hours. Ethiopian Airlines had leased the plane since September 2009. The aircraft’s previous owner was Ryanair.
Lightning striking aircraft during flights is not a rare occurrence: approximately 1 in every 2500 flights is struck by lightning. While lightning strikes can occur at any point during a flight, they usually (96% of reported cases) occur at altitudes lower than 25,000 feet (approximately 7.5km), during the descent and approach to landing, or when the plane is climbing after take-off.
In 40% of the reported cases of lightning strikes, the aircraft are undamaged, while in the other 60% of cases the lightning strikes damage some part of the aircraft, such as the onboard electronics or the aircraft’s skin and radar nose.
Fatal accidents in which lightning is a factor are rare, however. Since 1963 only 5 fatal accidents have been reported involving aircraft heavier than 5.7 tons. In each case the aircraft involved were older models, and in three of the 5 crashes the planes involved were smaller, twin-engine turbo planes. To date there are no proven fatal accidents involving modern jet aircraft.
Lightning strikes therefore are not considered a very serious problem for flight safety. Nevertheless, airline companies and aircraft manufacturers do focus attention on lightning strikes, because every aircraft that is struck by lightning must subsequently undergo comprehensive maintenance checks. These checks are time-consuming and therefore costly. For this reason, NLR, in collaboration with various European partners, researched the possibilities of equipping aircraft with devices that record the data about the nature and extent of the lightning strikes (the ILDAS project). Based on this recorded information, maintenance checks can then be performed much more efficiently.
In addition, substantial research is currently being conducted into protecting modern jet aircraft, which are increasingly constructed of composite materials, from lightning strikes.
The following is a list of the fatal crashes since 1963 involving lightning strikes on aircraft weighing more than 5.7 tons:
- 27/02/2002, Let 410 (twin-engine turbo prop), Comoros Islands, following a lightning strike, the artificial horizons and gyro compasses malfunctioned. The pilot lost control of the aircraft, one person onboard died.
- 10/1/2001, Merlin IV (twin-engine turbo prop), Mediterranean Sea, total failure of the electrical systems, all 10 people onboard died.
- 08/02/1988, Metro III (twin-engine turbo prop), Germany (Kettwig), total failure of the electrical systems, all 21 people onboard died.
- 24/12/1971, Lockheed L-188A Electra, combination of lightning and severe turbulence, all 9 people onboard died.
- 08/12/1963, B707, Philadelphia (USA), fuel tank explodes after a lightning strike, all 81 people onboard died.
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